44 research outputs found

    Effectiveness of predator satiation in masting oaks is negatively affected by conspecific density

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    La variación en la disponibilidad de las semillas da forma a las comunidades de plantas, y se ve fuertemente afectada por la depredación de las semillas. En algunas especies de plantas, la variación temporal en la producción de semillas es especialmente alta y está sincronizada en grandes áreas, lo que se denomina "siembra en mástil". Una ventaja selectiva de este fenómeno es la saciedad de los depredadores, que supone que la siembra en mástil ayuda a las plantas a escapar de la depredación de las semillas mediante la inanición de los depredadores en los años de escasez y la saciedad en los años de mástil. Sin embargo, aunque se puede predecir que la depredación de la semilla tiene un fuerte componente espacial y depende de las densidades de las plantas, apenas se ha investigado si la eficacia de la saciedad de los depredadores en las plantas de mastelero cambia según el efecto Janzen-Connell. Estudiamos, durante un período de 8 años, la producción de semillas, los patrones espacio-temporales de depredación de semillas de gorgojos y la abundancia de gorgojos adultos en una población de encinas (Quercus ilex) que consiste en árboles intercalados en parches que cubren un continuo de densidad conespecífica. Los robles aislados sacian eficazmente a los depredadores, pero esto es superado por el aumento de la densidad de plantas conespecíficas. La falta de saciedad de los depredadores en los árboles que crecen en parches densos fue causada por la redistribución de los insectos entre las plantas que probablemente los atenuó contra la escasez de alimentos en los años de escasez, y cambió el tipo de respuesta funcional del gorgojo del tipo II en los árboles aislados al tipo III en los árboles que crecían en parches densos. Este estudio proporciona la primera evaluación empírica de la noción de que el apareamiento y la saciedad del depredador deberían ser más importantes en las poblaciones que empiezan a dominar sus comunidades, y es coherente con la observación de que el apareamiento es menos frecuente y menos intenso en bosques diversos.Variation in seed availability shapes plant communities, and is strongly affected by seed predation. In some plant species, temporal variation in seed production is especially high and synchronized over large areas, which is called ‘mast seeding’. One selective advantage of this phenomenon is predator satiation which posits that masting helps plants escape seed predation through starvation of predators in lean years, and satiation in mast years. However, even though seed predation can be predicted to have a strong spatial component and depend on plant densities, whether the effectiveness of predator satiation in masting plants changes according to the Janzen-Connell effect has been barely investigated. We studied, over an 8-year period, the seed production, the spatiotemporal patters of weevil seed predation, and the abundance of adult weevils in a holm oak (Quercus ilex) population that consists of trees interspersed at patches covering a continuum of conspecific density. Isolated oaks effectively satiate predators, but this is trumped by increasing conspecific plant density. Lack of predator satiation in trees growing in dense patches was caused by re-distribution of insects among plants that likely attenuated them against food shortage in lean years, and changed the type of weevil functional response from type II in isolated trees to type III in trees growing in dense patches. This study provides the first empirical evaluation of the notion that masting and predator satiation should be more important in populations that start to dominate their communities, and is consistent with the observation that masting is less frequent and less intense in diverse forests.• National Science Foundation (Polonia). Becas Preludio 2015/17/N/ NZ8/01565, y Etiuda no. 2015/16/T/NZ8/00018, para Michał Bogdziewicz • Foundation for Polish Science Start Scholarship. Ayuda para para Michał Bogdziewicz • Gobierno de Extremadura. Programa de Atracción de Talento Investigador. Ayuda TA13032, para Raúl Bonal Andrés • Junta de Comunidades de Castilla-La Mancha/Fondo Social Europeo. Proyectos PII1C09-0256-9052 y PPII-2014-01-P • Ministerio de Economía y Competitividad de España y la Unión Europea Fondo de Desarrollo Regional. Proyecto AGL2014-54739-R (I+D+i) • Generalitat de Catalunya. Proyecto BEEMED (SGR913)peerReviewe

    Patient comprehension of oncologic surgical procedures using 3D printed surgical planning prototypes

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    Patient understanding of complex surgical procedures and post-intervention consequences is often poor. Little is known about the effectiveness of 3D printed models to improve the comprehension of the medical information provided to patients. The purpose of this study was to determine if 3D printed patient-specific anatomical models could help improve patients’ satisfaction and understanding of complex oncological surgical procedures, their risks, benefits, and alternatives. Basic procedure A randomized, controlled crossover experiment was performed, where subjects were randomly assigned to different treatments of the study. This experiment involved teenage patients experts from Kids Barcelona, a Young Person's Advisory Group. The team (n = 14, age range 14–20, 9 females and 5 males) was divided into two groups involved in two simulated pre-surgical outpatient visits for complex oncologic surgical procedures: a high-risk stage 4 abdominal neuroblastoma, and a biliary tract rhabdomyosarcoma. Two senior oncologic surgeons participated in the study by performing the structured outpatient pre-surgical visit. Each participant received information before the study explaining the study methodology and was given a questionnaire. Main findings Data analysis of the group using the 3D printed model for the neuroblastoma case showed better results than without the 3D model. On the other hand, conversely, on the data analysis of the rhabdomyosarcoma case with the 3D printed model no better results were observed as compared to the case of not using a 3D model. However, the results of the participants’ knowledge were still better than before the intervention. Satisfaction was significantly better with a 3D model in both cases.Peer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarPostprint (published version

    A state-of-the-art guide about the effects of sterilization processes on 3D-printed materials for surgical planning and medical applications: a comparative study

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    Surgeons use different medical devices in the surgery, such as patient-specific anatomical models, cutting and positioning guides, or implants. These devices must be sterilized before being used in the operation room. There are many sterilization processes available, with autoclave, hydrogen peroxide, and ethylene oxide being the most common in hospital settings. Each method has both advantages and disadvantages in terms of mechanics, chemical interaction, and post-treatment accuracy. The aim of the present study is to evaluate the dimensional and mechanical effect of the most commonly used sterilization techniques available in clinical settings, i.e., Autoclave 121, Autoclave 134, and hydrogen peroxide (HPO), on 11 of the most used 3D-printed materials fabricated using additive manufacturing technologies. The results showed that the temperature (depending on the sterilization method) and the exposure time to that temperature influence not only the mechanical behavior but also the original dimensioning planned on the 3D model. Therefore, HPO is a better overall option for most of the materials evaluated. Finally, based on the results of the study, a recommendation guide on sterilization methods per material, technology, and clinical application is presented.The research described in this paper was partially funded by the project named QuirofAM (Exp. COMRDI16-1-0011) and funded by ACCIÓ from the Catalan government and ERDF from European Union.Postprint (published version

    3D printed surgical planning prototype manufactured by a hybrid multi-material 3D printer

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    Surgical planning is a preoperative method of pre-visualization that is carried out before or during a surgical intervention in order to achieve the best outcome. This can be done either image-based or hands-on. Regarding the first strategy, it is based on the use of medical images. However, it has a huge limitation, which is the difficulty of identifying anatomical structures (crucial for surgeons to make correct decisions) and distances between tissues without any physical support. This problem is overcome with the use of 3D models. Despite this important development, until nowadays most of the surgical planning prototypes were 3D printed either using the moulding technique, which might take several days, or high-cost technologies as is material jetting. That is why, the present manuscript seeks to solve the problems arose by the use of a hybrid-multi material 3D printer which can not only use several materials at the time, but also two 3D printing technologies. The prototype introduced in this study is a neuroblastoma, a common cancer among children.Peer ReviewedPostprint (published version

    Negative schizophrenic symptoms as prefrontal cortex dysfunction: Examination using a task measuring goal neglect

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    Background: The negative symptoms of schizophrenia have been proposed to reflect prefrontal cortex dysfunction. However, this proposal has not been consistently supported in functional imaging studies, which have also used executive tasks that may not capture key aspects of negative symptoms such as lack of volition. Method: Twenty-four DSM-5 schizophrenic patients with high negative symptoms (HNS), 25 with absent negative symptoms (ANS) and 30 healthy controls underwent fMRI during performance of the Computerized Multiple Elements Test (CMET), a task designed to measure poor organization of goal directed behaviour or 'goal neglect'. Negative symptoms were rated using the PANSS and the Clinical Assessment Interview for Negative Symptoms (CAINS). Results: On whole brain analysis, the ANS patients showed no significant clusters of reduced activation compared to the healthy controls. In contrast, the HNS patients showed hypoactivation compared to the healthy controls in the left anterior frontal cortex, the right dorsolateral prefrontal cortex (DLPFC), the anterior insula bilaterally and the bilateral inferior parietal cortex. When compared to the ANS patients, the HNS patients showed reduced activation in the left anterior frontal cortex, the left DLPFC and the left inferior parietal cortex. After controlling for disorganization scores, differences remained in clusters in the left anterior frontal cortex and the bilateral inferior parietal cortex. Conclusions: This study provides evidence that reduced prefrontal activation, perhaps especially in the left anterior frontal cortex, is a brain functional correlate of negative symptoms in schizophrenia. The simultaneous finding of reduced inferior parietal cortex activation was unexpected, but could reflect this region's involvement in cognitive control, particularly the 'regulative' component of this

    Study protocol for a randomised, double-blinded, placebo-controlled phase III trial examining the add-on efficacy, cost-utility and neurobiological effects of low-dose naltrexone (LDN) in patients with fibromyalgia (INNOVA study)

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    Introduction There is evidence that low-dose naltrexone (LDN; <5.0 mg/day) reduces pain and improves the quality of life of people with fibromyalgia syndrome (FMS). However, no randomised controlled trials with long-term follow-ups have been carried out. The INNOVA study will evaluate the add-on efficacy, safety, cost-utility and neurobiological effects of LDN for reducing pain in patients with FMS, with a 1-year follow-up. Methods and analysis A single-site, prospective, randomised, double-blinded, placebo-controlled, parallel design phase III trial will be performed. Eligibility criteria include being adult, having a diagnosis of FMS and experiencing pain of 4 or higher on a 10-point numerical rating scale. Participants will be randomised to a LDN intervention group (4.5 mg/day) or to a placebo control group. Clinical assessments will be performed at baseline (T0), 3 months (T1), 6 months (T2) and 12 months (T3). The primary endpoint will be pain intensity. A sample size of 60 patients per study arm (120 in total), as calculated prior to recruitment for sufficient power, will be monitored between January 2022 and August 2024. Assessment will also include daily ecological momentary evaluations of FMS-related symptoms (eg, pain intensity, fatigue and sleep disturbance), and side effects via ecological momentary assessment through the Pain Monitor app during the first 3 months. Costs and quality-adjusted life years will be also calculated. Half of the participants in each arm will be scanned with MRI at T0 and T1 for changes in brain metabolites related to neuroinflammation and central sensitisation. Inflammatory biomarkers in serum will also be measured. Ethics and dissemination This study has been approved by the Ethics Committee of the Fundació Sant Joan de Déu. The results will be actively disseminated through peer-reviewed journals, conference presentations, social media and community engagement activities. Trial registration number NCT04739995

    Intracranial atherosclerotic plaque enhancement and long-term risk of future strokes: A prospective, longitudinal study

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    Background and Purpose The prognostic significance of postcontrast enhancement of intracranial atheromatous plaque is uncertain. Prospective, long-term follow-up studies in Caucasians, using a multicenter design, are lacking. We aimed to evaluate whether this radiological sign predicts long-term new stroke in symptomatic and asymptomatic intracranial atherosclerotic disease (ICAD) patients. Methods This was a prospective, observational, longitudinal, multicenter study. We included a symptomatic and an asymptomatic cohort of ICAD patients that underwent 3T MRI including high-resolution sequences focused on the atheromatous plaque. We evaluated grade of stenosis, plaque characteristics, and gadolinium enhancement ratio (postcontrast plaque signal/postcontrast corpus callosum signal). The occurrence of new events was evaluated at 3, 6, 9, and 12 months and annually thereafter. The association between plaque characteristics and new stroke was studied using Cox multiple regression survival analysis and Kaplan-Meier curves. Results Forty-eight symptomatic and 13 asymptomatic patients were included. During 56.3 ± 16.9 months, 11 patients (18%) suffered a new event (seven ischemic, two hemorrhagic, and two transient ischemic attacks). A receiver operating characteristic curve identified an enhancement ratio of >1.77 to predict a new event. In a multivariable Cox regression, postcontrast enhancement ratio >1.77 (hazard ratio [HR]= 3.632; 95% confidence interval [CI], 1.082-12.101) and cerebral microbleeds (HR = 5.244; 95% CI, 1.476-18.629) were independent predictors of future strokes. Patients with a plaque enhancement ratio >1.77 had a lower survival free of events (p < .05). Conclusions High intracranial postcontrast enhancement is a long-term predictor of new stroke in ICAD patients. Further studies are needed to elucidate whether postcontrast enhancement reflects inflammatory activity of intracranial atheromatous plaque.This study has been funded by the Spanish Ministry of Science, via FIS project PI13/02544, PI16/01396, and PI19/01398 and through the INVICTUS PLUS research network RD16/0019. Beatriz Gómez-Vicente received a research contract from the Junta de Castilla y León and European Social Fund, Spain. María Hernandez-Perez was funded by The Instituto de Salud Carlos III, Spain (JR17/00006)

    Adherence to european clinical practice guidelines for secondary prevention of cardiovascular disease : A cohort study

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    Funding: This study was supported by a grant from the Primary Health Care University Research Institute (IDIAP) Jordi Gol located in Barcelona, Spain (Grant ref: IDIAP 7Z12/006).To provide a better understanding of the actions taken within health systems and their results, this study aims to assess clinicians' adherence to clinical practice guidelines regarding recommended treatments in patients with cardiovascular disease in primary care settings, and to determine the associated factors. We conducted an ambispective cohort study in 21 primary care centres in 8 Spanish regions. Patients diagnosed with coronary heart disease, stroke and/or peripheral arterial disease were included. Patients who received the treatment recommended in the European guidelines on cardiovascular disease prevention (CPG's adherent group) were compared with patients who did not (CPG's non-adherent group). The outcome variables were cardiovascular hospital admissions, all-cause and cardiovascular mortality during follow-up. Of the 438 participants, 38.6% (n = 169) received the drug therapies recommended in the guidelines. The factors that increased the likelihood of good adherence to CPG's were being diagnosed with hypertension (p = 0.001), dyslipidaemia (p < 0.001) or diabetes (p = 0.001), and not having a psychiatric disorder (p = 0.005). We found no statistically significant association between good adherence to CPG's and lower incidence of events (p = 0.853). Clinician adherence to guidelines for secondary prevention of cardiovascular disease was low in the primary care setting

    Plasma Aβ42/40 ratio alone or combined with FDG-PET can accurately predict amyloid-PET positivity: a cross-sectional analysis from the AB255 Study

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    Background: To facilitate population screening and clinical trials of disease-modifying therapies for Alzheimer’s disease, supportive biomarker information is necessary. This study was aimed to investigate the association of plasma amyloid-beta (Aβ) levels with the presence of pathological accumulation of Aβ in the brain measured by amyloid-PET. Both plasma Aβ42/40 ratio alone or combined with an FDG-PET-based biomarker of neurodegeneration were assessed as potential AD biomarkers. Methods: We included 39 cognitively normal subjects and 20 patients with mild cognitive impairment from the AB255 Study who had undergone PiB-PET scans. Total Aβ40 and Aβ42 levels in plasma (TP42/40) were quantified using ABtest kits. Subjects were dichotomized as Aβ-PET positive or negative, and the ability of TP42/40 to detect Aβ-PET positivity was assessed by logistic regression and receiver operating characteristic analyses. Combination of plasma Aβ biomarkers and FDG-PET was further assessed as an improvement for brain amyloidosis detection and diagnosis classification. Results: Eighteen (30.5%) subjects were Aβ-PET positive. TP42/40 ratio alone identified Aβ-PET status with an area under the curve (AUC) of 0.881 (95% confidence interval [CI] = 0.779–0.982). Discriminating performance of TP42/40 to detect Aβ-PET-positive subjects yielded sensitivity and specificity values at Youden’s cutoff of 77.8% and 87.5%, respectively, with a positive predictive value of 0.732 and negative predictive value of 0.900. All these parameters improved after adjusting the model for significant covariates. Applying TP42/40 as the first screening tool in a sequential diagnostic work-up would reduce the number of Aβ-PET scans by 64%. Combination of both FDG-PET scores and plasma Aβ biomarkers was found to be the most accurate Aβ-PET predictor, with an AUC of 0.965 (95% CI = 0.913–0.100). Conclusions: Plasma TP42/40 ratio showed a relevant and significant potential as a screening tool to identify brain Aβ positivity in preclinical and prodromal stages of Alzheimer’s disease

    Effects and Mechanisms of Cognitive, Aerobic Exercise, and Combined Training on Cognition, Health, and Brain Outcomes in Physically Inactive Older Adults : The Projecte Moviment Protocol

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    Altres ajuts: It has also been rewarded with three pre-doctoral fellowships ( FPU014/01460, FI-2016, and FI-2018).Introduction: Age-related health, brain, and cognitive impairment is a great challenge in current society. Cognitive training, aerobic exercise and their combination have been shown to benefit health, brain, cognition and psychological status in healthy older adults. Inconsistent results across studies may be related to several variables. We need to better identify cognitive changes, individual variables that may predict the effect of these interventions, and changes in structural and functional brain outcomes as well as physiological molecular correlates that may be mediating these effects. Projecte Moviment is a multi-domain randomized trial examining the effect of these interventions applied 5 days per week for 3 months compared to a passive control group. The aim of this paper is to describe the sample, procedures and planned analyses. Methods: One hundred and forty healthy physically inactive older adults will be randomly assigned to computerized cognitive training (CCT), aerobic exercise (AE), combined training (COMB), or a control group. The intervention consists of a 3 month home-based program 5 days per week in sessions of 45 min. Data from cognitive, physical, and psychological tests, cardiovascular risk factors, structural and functional brain scans, and blood samples will be obtained before and after the intervention. Results: Effects of the interventions on cognitive outcomes will be described in intention-to-treat and per protocol analyses. We will also analyze potential genetic, demographic, brain, and physiological molecular correlates that may predict the effects of intervention, as well as the association between cognitive effects and changes in these variables using the per protocol sample. Discussion: Projecte Moviment is a multi-domain intervention trial based on prior evidence that aims to understand the effects of CCT, AE, and COMB on cognitive and psychological outcomes compared to a passive control group, and to determine related biological correlates and predictors of the intervention effects. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03123900
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